Potential Protective Effects of Antioxidants against Cyclophosphamide-Induced Nephrotoxicity

Suppression of glomerular damage, inflammation, apoptosis, and oxidative stress of acute kidney injury induced by cyclophosphamide toxicity using resveratrol in rat models

Cyclophosphamide (CP) is a chemotherapy drug that can be used to treat different types of cancers, but its nephrotoxicity effects restrict its usage in clinical settings. Currently, we examined whether the polyphenolic antioxidant and anti-inflammatory compound, resveratrol (RES), can protect against CP-induced nephrotoxicity. Twenty male mature Sprague-Dawley rats were divided into 4 groups of equal size: control group, RES group which received RES (20 mg/kg) for 15 consecutive days, CP group which received CP as a single dose (150 mg/kg) on day 16, and CP+RES group which was similar of the RES and CP groups. Tissue samples were obtained for the stereological, immunohistochemical, biochemical, and molecular evaluations. Findings showed that the numerical density of glomerulus, total volumes and interstitial tissue volumes of kidney, antioxidative biomarkers concentrations (CAT, GSH, SOD), and expression levels of OCT2 gene were notably greater in the CP+RES group than the CP group (P<0.05). During treatment, there was a significant decrease in the serum levels of the urea and creatinine, the densities of apoptotic and inflammatory cells, as well as levels of MDA and proinflammatory cytokines (IL-1β, TNF-α, and PFN1) in the CP+RES group than the CP group (P<0.05). We deduce that giving RES can suppress of glomerular damage, inflammation, apoptosis, and oxidative stress of acute kidney injury induced by CP toxicity.

The nephroprotective effect of Quercetin in Cyclophosphamide-induced renal toxicity might be associated with MAPK/ERK and NF-κB signal modulation activity

The present study aimed to examine the protective effect of quercetin (QUE) on cyclophosphamide (CTX)-induced nephrotoxicity. For that purpose, 24 mice were divided into four groups (Control, QUE, CTX, and CTX + QUE). The CTX and CTX + QUE groups received 200 mg/kg of cyclophosphamide on the 1st and 7th days. The QUE and CTX + QUE groups were treated with 50 mg/kg of quercetin daily for 14 days. At the end of the experiment, the animals were sacrificed, and kidney samples were analyzed. The results indicated that CTX leads to severe morphological degenerations and disruption in renal function. Serum BUN, Creatinine, Uric acid, tissue Bax, Caspase 3, TNF-α and IL-1β expression levels were upregulated in the CTX group compared to Control and QUE groups (p < 0.05). Although MAPK/ERK phosphorylation level is not affected in CTX group, there was a significant increase in CTX + QUE group (p < 0.05), but the NF-κB was significantly suppressed in this group (p < 0.01). The RT-qPCR results showed that the cyt-c and the Bax/Bcl-2 ratio mRNA expression folds were upregulated in the CTX group (p < 0.01), which was downregulated in the CTX + QUE group. However, there was a significant difference in the CTX + QUE group compared to the Control and QUE groups (p < 0.01). The findings showed that administering quercetin along with cyclophosphamide alleviated renal injury by regulating apoptotic and inflammatory expression. Moreover, the administration of quercetin and cyclophosphamide could synergistically improve renal function test results, and activate cellular responses, which upmodulate MAPK/ERK phosphorylation and suppression of NF-κB.

Strengths and limitations of the worm development and activity test (wDAT) as a chemical screening tool for developmental hazards

The worm Development and Activity Test (wDAT) measures C. elegans developmental milestone acquisition timing and stage-specific spontaneous locomotor activity (SLA). Previously, the wDAT identified developmental delays and SLA level changes in C. elegans with mammalian developmental toxicants arsenic, lead, and mercury. 5-fluorouracil (5FU), cyclophosphamide (CP), hydroxyurea (HU), and ribavirin (RV) are teratogens that also induce growth retardation in developing mammals. In at least some studies on each of these chemicals, fetal weight reductions were seen at mammalian exposures below those that had teratogenic effects, suggesting that screening for developmental delay in a small alternative whole-animal model could act as a general toxicity endpoint to identify chemicals for further testing for more specific adverse developmental outcomes. Consistent with mammalian developmental effects, 5FU, HU, and RV were associated with developmental delays with the wDAT. Exposures associated with developmental delay induced hypoactivity with 5FU and HU, but slight hyperactivity with RV. CP is a prodrug that requires bioactivation by cytochrome P450s for both therapeutic and toxic effects. CP tests as a false negative in several in vitro assays, and it was also a false negative with the wDAT. These results suggest that the wDAT has the potential to identify some developmental toxicants, and that a positive wDAT result with an unknown may warrant further testing in mammals. Further assessment with larger panels of positive and negative controls will help qualify the applicability and utility of this C. elegans wDAT assay within toxicity test batteries or weight of evidence approaches for developmental toxicity assessment.

Boswellic Acid and Betulinic Acid Pre-treatments Can Prevent the Nephrotoxicity Caused by Cyclophosphamide Induction

Cyclophosphamide (CYP) is a chemotherapeutic drug used to treat various cancers. However, its clinical use is limited due to severe organ damage, particularly to the kidneys. While several phytochemicals have been identified as potential therapeutic targets for CYP nephrotoxicity, the nephroprotective effects of boswellic acid (BOSW) and betulinic acid (BET) have not yet been investigated. Our study used 42 rats divided into six equal groups. The study included six groups: control, CYP (200 mg/kg), CYP+BOSW20 (20 mg/kg), CYP+BOSW40 (40 mg/kg), CYP+BET20 (20 mg/kg), and CYP+BET40 (40 mg/kg). The pre-treatments with BOSW and BET lasted for 14 days, while the application of cyclophosphamide was performed intraperitoneally only on the 4th day of the study. After the experimental protocol, the animals were sacrificed, and their kidney tissues were isolated. Renal function parameters, histological examination, oxidative stress, and inflammation parameters were assessed both biochemically and at the molecular level in kidney tissue. The results showed that oxidative stress and inflammatory response were increased in the kidney tissue of rats treated with CYP, leading to impaired renal histology and function parameters (p < 0.05). Oral administration of both doses of BET and especially high doses of BOSW improved biochemical, oxidative, and inflammatory parameters significantly (p < 0.05). Histological studies also showed the restoration of normal kidney tissue architecture. BOSW and BET have promising biological activity against CYP-induced nephrotoxicity by attenuating inflammation and oxidative stress and enhancing antioxidant status.

Mechanisms of oxidative stress in interstitial cystitis/bladder pain syndrome

Interstitial cystitis/bladder pain syndrome (IC/BPS) is characterized by bladder and/or pelvic pain, increased urinary urgency and frequency and nocturia. The pathophysiology of IC/BPS is poorly understood, and theories include chronic inflammation, autoimmune dysregulation, bacterial cystitis, urothelial dysfunction, deficiency of the glycosaminoglycan (GAG) barrier and urine cytotoxicity. Multiple treatment options exist, including behavioural interventions, oral medications, intravesical instillations and procedures such as hydrodistension; however, many clinical trials fail, and patients experience an unsatisfactory treatment response, likely owing to IC/BPS phenotype heterogeneity and the use of non-targeted interventions. Oxidative stress is implicated in the pathogenesis of IC/BPS as reactive oxygen species impair bladder function via their involvement in multiple molecular mechanisms. Kinase signalling pathways, nociceptive receptors, mast-cell activation, urothelial dysregulation and circadian rhythm disturbance have all been linked to reactive oxygen species and IC/BPS. However, further research is necessary to fully uncover the role of oxidative stress in the pathways driving IC/BPS pathogenesis. The development of new models in which these pathways can be manipulated will aid this research and enable further investigation of promising therapeutic targets.

Nephroprotective Effect of Bergapten Against Cyclophosphamide-Mediated Renal Stress, Inflammation, and Fibrosis in Wistar Rats: Probable Role of NF-kB and TGF-β1 Signaling Molecules

Cyclophosphamide (CPM) is a well-established antineoplastic drug with marked clinical outcomes in various types of cancers. Despite being a promising drug, its use is associated with significant renal toxicity and often limits its use, leading to compromised clinical outcomes. Therefore, this study explored the renal protective effect of bergapten (BGP), a natural bioactive compound that showed marked antioxidant, anti-inflammatory, anticancer, and neuroprotective effects. Till now, BGP has not been studied for its renal protective effect in an in vivo model. Animals were divided into control, toxic, BGP-3, BGP-10, and BGP Per se. The control group was treated with normal saline for 2 weeks. To the toxic group, CPM 200 mg/kg was given on day 7 as i.p. To BGP-3, 10, and Per se, BGP-3 and 10 mg/kg, ip was given 2 weeks with a single shot of CPM 200 day 7. To the Per se group, only BGP 10 mg/kg, ip was given from day 1 to day 14. After 14 days, animals were sacrificed, and kidneys were removed and studied for the markers of oxidative stress, inflammation, renal injury, renal fibrosis, and renal damage using biochemical, histopathological, and immunohistochemical studies. We found that BGP-10 effectively reversed the damage toward normal, whereas BGP-3 failed to exhibit a significant renal protective effect. We conclude that bergapten could be a potential renal protective drug, and hence, more detailed cellular molecular-based studies are needed to bring this drug from the bench to the bedside.

Cardioprotective role of a magnolol and honokiol complex in the prevention of doxorubicin-mediated cardiotoxicity in adult rats

Doxorubicin (DOXO) induces marked cardiotoxicity, though increased oxidative stress while there are some documents related with cardioprotective effects of some antioxidants against organ-toxicity during cancer treatment. Although magnolia bark has some antioxidant-like effects, its action in DOXO-induced heart dysfunction has not be shown clearly. Therefore, here, we aimed to investigate the cardioprotective action of a magnolia bark extract with active component magnolol and honokiol complex (MAHOC; 100 mg/kg) in DOXO-treated rat hearts. One group of adult male Wistar rats was injected with DOXO (DOXO-group; a cumulative dose of 15 mg/kg in 2-week) or saline (CON-group). One group of DOXO-treated rats was administered with MAHOC before DOXO (Pre-MAHOC group; 2-week) while another group was administered with MAHOC following the 2-week DOXO (Post-MAHOC group). MAHOC administration, before or after DOXO, provided full survival of animals during 12-14 weeks, and significant recoveries in the systemic parameters of animals such as plasma levels of manganese and zinc, total oxidant and antioxidant statuses, and also systolic and diastolic blood pressures. This treatment also significantly improved heart function including recoveries in end-diastolic volume, left ventricular end-systolic volume, heart rate, cardiac output, and prolonged P-wave duration. Furthermore, the MAHOC administrations improved the structure of left ventricles such as recoveries in loss of myofibrils, degenerative nuclear changes, fragmentation of cardiomyocytes, and interstitial edema. Biochemical analysis in the heart tissues provided the important cardioprotective effect of MAHOC on the redox regulation of the heart, such as improvements in activities of glutathione peroxidase and glutathione reductase, and oxygen radical-absorbing capacity of the heart together with recoveries in other systemic parameters of animals, while all of these benefits were observed in the Pre-MAHOC treatment group, more prominently. Overall, one can point out the beneficial antioxidant effects of MAHOC in chronic heart diseases as a supporting and complementing agent to the conventional therapies.

The hepatoprotective effects of sitagliptin against cyclophosphamide-induced hepatotoxicity in rat

Hepatotoxicity is a serious side effects of cyclophosphamide. Thus, the present research investigates the protective properties of sitagliptin against cyclophosphamide-induced hepatotoxicity. Fifty male rats were randomly divided into five groups. They were pre-treated with either sitagliptin or normal saline once a day for the first ten days of the study. To induce acute hepatotoxicity, cyclophosphamide (200 mg/kg, i.p) was injected only one time and 45 min after the last dose of sitagliptin. The rats were sacrificed on the 11th day, and their blood and liver were collected for biochemical, gene expression, and histopathological assessments. Our results showed that cyclophosphamide induced obvious liver toxicity as marked by an increase in serum levels of alanine transaminase and aspartate transaminase, reduced serum albumin and total protein levels, in addition to histopathological changes. The malondialdehyde, tumor necrosis factor-α, and interleukin-6 levels were also elevated and total antioxidant capacity declined in serum and hepatic homogenates. Sitagliptin magnificently attenuated the cylophosphamide-induced histological alterations, improved liver function tests, enhanced total antioxidant capacity, and decreased malondialdehyde, tumor necrosis factor-α, and interleukin-6 in the blood and hepatic tissues. These findings suggest that sitagliptin has hepatoprotective activity against cyclophosphamide toxicity, which may be due to its antioxidant and anti-inflammatory effects.

Oral delivery of nerolidol alleviates cyclophosphamide-induced renal inflammation, apoptosis, and fibrosis via modulation of NF-κB/cleaved caspase-3/TGF-β signaling molecules

Cyclophosphamide (CP) is one of the most extensively used antineoplastic drug, but the nephrotoxicity caused by this drug is a major limiting factor for its use. Nerolidol (NERO) is a natural bioactive compound with diverse pharmacological actions. In Vitro and in vivo study was performed using HK-2 renal cells and Swiss Albino mice. Cell lines and animals were treated with NERO 25 and 50 µM + 30 µM CP (in vitro), 200 and 400 mg/kg, p.o. NERO from day 1 to day 15 + 200 mg/kg, i.p. CP on day 17 as single intraperitoneal injection (in vivo). The makers of oxidative stress, renal-specific injury markers, inflammation, apoptosis, fibrosis, and histopathological changes were studied. The study's outcome showed a significant reduction in the level of malonaldehyde and interleukin-6 (p < 0.01), tumor necrosis factor-α, IL-1β (p < 0.001), and an increase in the superoxide dismutase, catalase, glutathione and interleukin-10 level (p < 0.01), in the in vivo study when treated with NERO 400 and compared with CP 200. In Vitro study showed reduced expression of nuclear factor kappa light chain enhancer of activated B cells, cleaved caspase-3, kidney injury molecule-1 and transforming growth factor-β-1 (p < 0.001), when treated with NERO 50 µM whereas NERO 25 µM only reduced the level of cleaved caspase-3 (p < 0.05) when compared with 30 µM. NERO 400 also reduced uric acid (p < 0.05), urea (p < 0.01), blood urea nitrogen, and serum creatinine levels (p < 0.001) and increased the level of blood-urea-nitrogen/creatinine ratio (p < 0.001). Additionally, the level of fibrosis-specific markers such as transforming growth factor-β1, hyaluronic acid (p < 0.01), 4-hydroxyproline, a collagen-rich area in Masson's' trichome stain, and Smad3 expression was also significantly reduced (p < 0.001). Furthermore, the outcome of multiple renal staining showed structural reversal aberrations, reduction of the thick basement membrane, and glycogen level toward normal when treated with NERO 400. Thus, the study showed a novel mechanistic modality of NERO against cyclophosphamide-induced renal toxicity. The outcome of this study can be considered a step closer to the development of an adjuvant to mitigate cyclophosphamide-induced renal toxicity among patients treated with cyclophosphamide.

Protective potential of pterostilbene against cyclophosphamide-induced nephrotoxicity and cystitis in rats

PURPOSE

Cyclophosphamide (CYP) is an antitumor drug. However, in addition to its antitumor affect, CYP can also lead to nephrotoxicity and hemorrhagic cystitis. The purpose of this study was to investigate the potential protective effects of Pterostilbene (Pte), a natural antioxidant as a resveratrol analog against CYP-induced nephrotoxicity and cystitis in rats.

METHODS

Twenty-one male Sprague Dawley rats were divided into 3 equal groups. The control group and the CYP group (CYPG) received 1 ml/kg sunflower oil per day, and the CYP + Pte group (CYP + PteG) 40 mg/kg per day Pte dissolved in sunflower oil once a day via the oral route for 14 days. In addition, on day 9 of the experiment, CYPG and CYP + PteG received a single dose of 200 mg/kg CYP dissolved in saline solution, while the control group received a single dose of 10 ml/kg saline solution, via the intraperitoneal route. Bladder and kidney tissues were collected for histological and biochemical evaluations.

RESULTS

Pte was observed to reduce CYP-derived increases in malondialdehyde level, total oxidant status (TOS), the oxidative stress index (OSI), and apoptosis in kidney tissues and to cause an increase in superoxide dismutase levels. It also reduced CYP-derived increases in TOS, OSI, and apoptosis in bladder tissue. Moreover, Pte also ameliorated histopathological findings associated with CYP-induced tissue damage in both the kidney and bladder.

CONCLUSION

Our study findings show that Pte may exhibit a protective effect against CYP-induced nephrotoxicity and cystitis.

Redox Regulation of Nrf2 in Cisplatin-Induced Kidney Injury

Cisplatin, a potent chemotherapeutic agent, is marred by severe nephrotoxicity that is governed by mechanisms involving oxidative stress, inflammation, and apoptosis pathways. The transcription factor Nrf2, pivotal in cellular defense against oxidative stress and inflammation, is the master regulator of the antioxidant response, upregulating antioxidants and cytoprotective genes under oxidative stress. This review discusses the mechanisms underlying chemotherapy-induced kidney injury, focusing on the role of Nrf2 in cancer therapy and its redox regulation in cisplatin-induced kidney injury. We also explore Nrf2's signaling pathways, post-translational modifications, and its involvement in autophagy, as well as examine redox-based strategies for modulating Nrf2 in cisplatin-induced kidney injury while considering the limitations and potential off-target effects of Nrf2 modulation. Understanding the redox regulation of Nrf2 in cisplatin-induced kidney injury holds significant promise for developing novel therapeutic interventions. This knowledge could provide valuable insights into potential strategies for mitigating the nephrotoxicity associated with cisplatin, ultimately enhancing the safety and efficacy of cancer treatment.

Cytoprotective remedies for ameliorating nephrotoxicity induced by renal oxidative stress

AIMS

Nephrotoxicity is the hallmark of anti-neoplastic drug metabolism that causes oxidative stress. External chemical agents and prescription drugs release copious amounts of free radicals originating from molecular oxidation and unless sustainably scavenged, they stimulate membrane lipid peroxidation and disruption of the host antioxidant mechanisms. This review aims to provide a comprehensive collection of potential cytoprotective remedies in surmounting the most difficult aspect of cancer therapy as well as preventing renal oxidative stress by other means.

MATERIALS AND METHODS

Over 400 published research and review articles spanning several decades were scrutinised to obtain the relevant data which is presented in 3 categories; sources, mechanisms, and mitigation of renal oxidative stress.

KEY-FINDINGS

Drug and chemical-induced nephrotoxicity commonly manifests as chronic or acute kidney disease, nephritis, nephrotic syndrome, and nephrosis. Renal replacement therapy requirements and mortalities from end-stage renal disease are set to rapidly increase in the next decade for which 43 different cytoprotective compounds which have the capability to suppress experimental nephrotoxicity are described.

SIGNIFICANCE

The renal system performs essential homeostatic functions that play a significant role in eliminating toxicants, and its accumulation and recurrence in nephric tissues results in tubular degeneration and subsequent renal impairment. Global statistics of the latest chronic kidney disease prevalence is 13.4 % while the end-stage kidney disease requiring renal replacement therapy is 4-7 million per annum. The remedial compounds discussed herein had proven efficacy against nephrotoxicity manifested consequent to impaired antioxidant mechanisms in preclinical models produced by renal oxidative stress activators.

Histological study of the role of CD34+ stem cells and mast cells in cyclophosphamide-induced thymic injury in rats and the possible attenuating role of melatonin

Cyclophosphamide (CP) is an anticancer drug that adversely affects immunity and thymus structure. Melatonin is a hormone secreted by the pineal gland. It boosts immunity and has antioxidant properties. Therefore, the present study was conducted to investigate the possible protective effect of melatonin on CP-induced changes in the rat thymus. Forty male albino rats were used and divided equally into four main groups. Group I was the control group. Group II (melatonin group) received melatonin at a dose of 10 mg/kg body weight/day by intraperitoneal injection throughout the experimental period. Group III (CP group) received 200 mg/kg body weight CP by a single intraperitoneal injection. Group IV (CP + melatonin group) received melatonin intraperitoneally at a dose of 10 mg/kg body weight/day starting 5 days prior to CP injection until the end of the experiment. All rats were euthanized 7 days after CP injection. Administration of CP in group III resulted in depletion of the cortical thymoblasts. In addition, CD34-immunopositive stained stem cells decreased and mast cell infiltration increased. Electron microscopy showed degeneration of thymoblasts and vacuolization of epithelial reticular cells. Administration of melatonin with CP in group IV showed considerable protection of thymic histology. In conclusion, melatonin may protect against CP-induced thymic injury.

Biochemical, Histological, and Ultrastructural Studies of the Protective Role of Vitamin E on Cyclophosphamide-Induced Cardiotoxicity in Male Rats

BACKGROUND

Cyclophosphamide (CP) (Cytoxan or Endoxan) is an efficient anti-tumor agent, widely used for the treatment of various neoplastic diseases. The study aimed to investigate the protective role of vitamin E (vit E) in improving cardiotoxicity in rats induced by CP.

MATERIALS AND METHODS

Forty male Wistar rats were divided randomly into four experimental groups (each consisting of ten rats); the control group was treated with saline. The other three groups were treated with vit E, CP, and the combination of vit E and CP. Serum lipid profiles, enzyme cardiac biomarkers, and cardiac tissue antioxidants were evaluated, as well as histological and ultrastructure investigations.

RESULTS

CP-treated rats showed a significant increase in serum levels of cardiac markers (troponin, CK, LDH, AST, and ALT), lipid profiles, a reduction in the antioxidant enzyme activities (CAT, SOD, and GPx), and an elevation in the level of lipid peroxidation (LPO). The increase in the levels of troponin, LDH, AST, ALP, and triglycerides is a predominant indicator of cardiac damage due to the toxic effect of CP. The biochemical changes parallel cardiac injuries such as myocardial infarction, myocarditis, and heart failure. Vitamin E played a pivotal role, as it attenuated most of these changes because of its ability to scavenge free radicals and reduce LPO. In addition, vit E was found to improve the histopathological alterations caused by CP where no evidence of damage was observed in the cardiac architecture, and the cardiac fibers had regained their normal structure with minimal hemorrhage.

CONCLUSIONS

As a result of its antioxidant activity and its stabilizing impact on the cardiomyocyte membranes, vit E is recommended as a potential candidate in decreasing the damaging effects of CP.

A Synopsis of Current Theories on Drug-Induced Nephrotoxicity

The overriding goal of the treatment of patients is its effectiveness and safety. However, all medications currently being used also exert some adverse pharmaceutical reactions, which may be regarded as an unintended but inevitable cost of pharmacotherapy. The kidney, as the main organ that eliminates xenobiotics, is an organ especially predisposed and vulnerable to the toxic effects of drugs and their metabolites during their excretion from the body. Moreover, some drugs (e.g., aminoglycosides, cyclosporin A, cisplatin, amphotericin B, and others) have a "preferential" nephrotoxicity potential, and their use is associated with an increased risk of kidney damage. Drug nephrotoxicity is, therefore, both a significant problem and a complication of pharmacotherapy. It should be noted that, currently, there is no generally recognized definition of drug-induced nephrotoxicity and no clear criteria for its diagnosis. This review briefly describes the epidemiology and diagnosis of drug-induced nephrotoxicity and characterizes its pathomechanisms, including immunological and inflammatory disturbances, altered kidney blood flow, tubulointerstitial injury, increased lithogenesis-crystal nephropathy, rhabdomyolysis, and thrombotic microangiopathy. The study also lists the basic drugs with nephrotoxicity potential and provides a short overview of the preventive methods for reducing the risk of drug-related kidney damage developing.

Anti-inflammatory and anti-apoptotic potential of beta-glucan on chemotherapy-induced nephrotoxicity in rats

Background/Aim: Cyclophosphamide (CP) is an anti-cancer agent that mediates nephrotoxicity. Beta (β)-glucan has restorative effects on kidney toxicities through its antioxidant potential; however, the effects of β-glucan on CP-induced renal injury remain unknown. In an experimental nephrotoxicity model using rats, we sought to examine the potential protective action of β-glucan on kidney histomorphology, apoptosis, and TNF-α expression. Methods: Male albino Wistar rats were divided equally into four groups: control, CP, β-glucan, and CP+β-glucan. The kidney tissues of the rats were examined for TNF-α and caspase-3 immunostaining to evaluate inflammation and apoptosis, respectively. Hematoxylin and eosin (H&E) and periodic acid–Schiff (PAS) staining were used for histopathological analyses. Results: The CP group showed severe histopathological damage in the renal tissues of rats. In the renal tissue of the CP group, immunoreactivities for TNF-α (1.25 [0.079] and caspase-3 (1.506 [0.143] were also higher than the control group (0.117 [0.006] and 0.116 [0.002], respectively; P<0.001). In the CP+β-glucan group, the histopathological changes significantly improved. Conclusion: Beta-glucan has therapeutic potential against CP-induced nephrotoxicity in rat kidney.

The Effect of Oxidative Phosphorylation on Cancer Drug Resistance

Recent studies have shown that oxidative phosphorylation (OXPHOS) is a target for the effective attenuation of cancer drug resistance. OXPHOS inhibitors can improve treatment responses to anticancer therapy in certain cancers, such as melanomas, lymphomas, colon cancers, leukemias and pancreatic ductal adenocarcinoma (PDAC). However, the effect of OXPHOS on cancer drug resistance is complex and associated with cell types in the tumor microenvironment (TME). Cancer cells universally promote OXPHOS activity through the activation of various signaling pathways, and this activity is required for resistance to cancer therapy. Resistant cancer cells are prevalent among cancer stem cells (CSCs), for which the main metabolic phenotype is increased OXPHOS. CSCs depend on OXPHOS to survive targeting by anticancer drugs and can be selectively eradicated by OXPHOS inhibitors. In contrast to that in cancer cells, mitochondrial OXPHOS is significantly downregulated in tumor-infiltrating T cells, impairing antitumor immunity. In this review, we summarize novel research showing the effect of OXPHOS on cancer drug resistance, thereby explaining how this metabolic process plays a dual role in cancer progression. We highlight the underlying mechanisms of metabolic reprogramming in cancer cells, as it is vital for discovering new drug targets.